1. Technical Field
The present disclosure relates to surgical apparatus for suturing body tissue and more particularly to surgical suturing apparatus which passes a needle between its jaws.
2. Background of Related Art
During minimally invasive (endoscopic) surgical procedures, suturing of body tissue can be time consuming for the surgeon. In such endoscopic procedures, where surgery is performed in a body cavity and access to the site is through trocar cannulas, suturing is especially difficult. The surgeon cannot grasp the needle as in open surgery, but must rely on grasping instruments to grasp and maneuver the needle in the remote surgical site. These instruments entail grasping the surgical needle between the instrument jaws and manipulating the needle through the body tissue. Oftentimes, a second grasping instrument is required to enable passing the needle between the two instruments in the same manner the surgeon passes the needle during open procedures. Not only is maneuverability difficult, but the needle could slip from the jaws into the body cavity.
To this end, the instrument disclosed in EPO application 92308849.6 was developed. This instrument advantageously provides the surgeon with unprecedented control during suturing in endoscopic procedures. The surgical needle is passed between the jaws of the instrument and is retained in one of the jaws as they are opened. This instrument provides a marked advance over the earlier laparoscopic/endoscopic techniques of suturing. An improvement to the instrument disclosed in EPO Patent Application No. 92308849.6 is disclosed in U.S. patent application Ser. No. 08/134,145, filed Oct. 8, 1993. One of the advantages of this later instrument is that it provides a disposable loading unit which enables the apparatus to be reloaded with a fresh needle and suture.
The advantages attendant passing and retaining a surgical needle between instrument jaws is not limited to endoscopic applications. For example, in open vascular surgery, due to the extremely small size of the surgical needles, it is sometimes difficult for the surgeon to manipulate the needles between his/her hands. Additionally, the surgery is often performed under magnification and the surgeon's repeated steps of focusing on the surgical site to pass the needle through the tissue, focusing away from the surgical site to pass the needle between his hands in preparation for the next stitch, and then re-focusing on the surgical site to continue stitching, is tiring, time consuming and can cause eye strain. The same difficulties of re-focusing and eye strain are encountered if the surgeon uses needle graspers to grasp the needle and pass it through one vessel and then the opposite vessel to thread or impart a series of stitches to the vessels to suture them together.
Because of the extremely small size of the suturing needle used in vascular surgery, typically on the order of ten thousands of an inch in diameter, handling problems may also arise while manipulating the suturing needle through the vascular tissues. For example, upon piercing a vessel, the needle must be pushed through the vessel, released by the needle holder at or e end of the needle and subsequently grasped at the opposite end of the needle to draw the needle and suture through the vessel thus requiring the release of the needle and suture during the procedure. Release of the needle is often undesirable and may pose problems in regaining control of the needle. To avoid this, it may become necessary to use two needle holders, one positioned on either side of the vessel, to continually grasp the needle, thereby requiring two hands to perform the operation. Additionally, precise control of the needle is often difficult when using typical needle holders. The small size of the needle also makes it difficult to recover the needle if dropped during the surgical procedures, especially during endoscopic procedures if it is dropped in the body cavity.
These problems become magnified when the vascular surgical procedures are carried out endoscopically or laparoscopically. While providing illumination and vision, endoscopes typically have a restricted or reduced field of view. Thus, during a suturing operation, as the needle and suture material are passed through the vessels and pulled to draw the suture material through, it often becomes necessary to move the needle holder suturing apparatus from the field of view and may present problems in repositioning the needle within the restricted field of view to form another stitch in the vascular tissues. This increases the time required to suture the vessels together. Additionally, there is a limited space for maneuverability inside the body cavity and limited access to the body tissue, thus making endoscopic suturing quite difficult. The aforementioned minute size of the vessels and vascular surgical needles also add to the difficulty of endoscopic vascular suturing.
Thus, it would be advantageous to have a vascular surgical suturing apparatus for suturing vessels, and particularly suited to suturing vascular tissues endoscopically or laparoscopically. It would also be advantageous to have a vascular surgical suturing apparatus which is capable of maintaining precise and constant control of the vascular needle as it is passed from one needle holding jaw of the apparatus to another to avoid release of the needle during the suturing operation. It would be further advantageous to have a vascular surgical suturing apparatus which is capable of suturing vascular tissue sections together with limited apparatus and needle movement in order to maintain the entire suturing operation within a restricted field of view. An instrument which passes the needle between the jaws would overcome the difficulties by allowing the surgeon to continuously focus on the surgical site during the entire vessel stitching procedure. It would be particularly advantageous to provide a suturing apparatus having jaw structures movable longitudinally with respect to a body portion. It would also be advantageous to provide a suturing apparatus which could accommodate current curved vascular needles without requiring use of a specifically designed needle. It would additionally be advantageous to provide a suturing apparatus which transfers a needle between jaws in response to repeated actuation of one or more control levers.